Add BT1035 pairing and station presets (fw 0.7.0).

Expose discoverable mode and A2DP control over REST, add persisted
DAB/FM preset list with web UI, and document gaps in docs/TODO.md.

Co-authored-by: Cursor <cursoragent@cursor.com>

Software/components/services/bluetooth/CMakeLists.txt

@@ -0,0 +1,8 @@
+idf_component_register(
+    SRCS
+        "src/BluetoothService.cpp"
+    INCLUDE_DIRS "include"
+    REQUIRES core bt1035
+)
+
+target_compile_features(${COMPONENT_LIB} PUBLIC cxx_std_23)

Software/components/services/bluetooth/include/bluetooth/BluetoothService.hpp

@@ -0,0 +1,102 @@
+/**
+ * @file    BluetoothService.hpp
+ * @brief   Intent-level Bluetooth API for HTTP and UI.
+ *
+ * DigiRadio firmware — https://github.com/manvalan/DigiRadio
+ *
+ * Copyright 2026 Michele Bigi
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * @author  Michele Bigi
+ * @date    2026-07-06
+ */
+#pragma once
+
+#include "bt1035/Bt1035Driver.hpp"
+#include "bt1035/Bt1035Error.hpp"
+#include "core/BluetoothJson.hpp"
+
+#include <expected>
+
+namespace bluetooth {
+
+/**
+ * @brief    BluetoothService — pairing and A2DP status for the web API.
+ *
+ * @dname    BluetoothService
+ * @return   n/a (type)
+ * @pubstate Borrows bt1035::Bt1035Driver for the process lifetime. Tracks
+ *           whether discoverable mode was requested via startPairing().
+ *
+ * @author   Michele Bigi
+ * @date     2026-07-06
+ */
+class BluetoothService {
+public:
+    /**
+     * @brief    BluetoothService — bind to the BT1035 driver.
+     *
+     * @dname    BluetoothService
+     * @param    driver  Booted BT1035 driver (must outlive this service).
+     * @pubstate stores driver reference; pairing inactive initially.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    explicit BluetoothService(bt1035::Bt1035Driver& driver);
+
+    /**
+     * @brief    refreshStatus — read module boot, pairing, and A2DP state.
+     *
+     * @dname    refreshStatus
+     * @return   BluetoothStatus on success, or Bt1035Error from the driver.
+     * @pubstate queries driver for A2DP state when booted.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    [[nodiscard]] std::expected<core::BluetoothStatus, bt1035::Bt1035Error>
+    refreshStatus();
+
+    /**
+     * @brief    startPairing — enter discoverable mode (AT+PAIR=1).
+     *
+     * @dname    startPairing
+     * @return   Ok on success, or Bt1035Error.
+     * @pubstate sets pairingActive_ on success.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    [[nodiscard]] std::expected<void, bt1035::Bt1035Error> startPairing();
+
+    /**
+     * @brief    stopPairing — leave discoverable mode (AT+PAIR=0).
+     *
+     * @dname    stopPairing
+     * @return   Ok on success, or Bt1035Error.
+     * @pubstate clears pairingActive_ on success.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    [[nodiscard]] std::expected<void, bt1035::Bt1035Error> stopPairing();
+
+    /**
+     * @brief    disconnect — release the active A2DP link (AT+A2DPDISC).
+     *
+     * @dname    disconnect
+     * @return   Ok on success, or Bt1035Error.
+     * @pubstate delegates to driver.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    [[nodiscard]] std::expected<void, bt1035::Bt1035Error> disconnect();
+
+private:
+    bt1035::Bt1035Driver& driver_;
+    bool pairingActive_;
+};
+
+} // namespace bluetooth

Software/components/services/bluetooth/src/BluetoothService.cpp

@@ -0,0 +1,68 @@
+/**
+ * @file    BluetoothService.cpp
+ * @brief   BluetoothService implementation.
+ *
+ * DigiRadio firmware — https://github.com/manvalan/DigiRadio
+ *
+ * Copyright 2026 Michele Bigi
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * @author  Michele Bigi
+ * @date    2026-07-06
+ */
+
+#include "bluetooth/BluetoothService.hpp"
+
+namespace bluetooth {
+
+BluetoothService::BluetoothService(bt1035::Bt1035Driver& driver)
+    : driver_(driver)
+    , pairingActive_(false)
+{
+}
+
+std::expected<core::BluetoothStatus, bt1035::Bt1035Error>
+BluetoothService::refreshStatus()
+{
+    core::BluetoothStatus status{
+        .booted = driver_.isBooted(),
+        .pairing = pairingActive_,
+        .a2dpState = core::Bt1035A2dpState::Standby,
+    };
+
+    if (!status.booted) {
+        return status;
+    }
+
+    auto a2dp = driver_.queryA2dpState();
+    if (!a2dp) {
+        return std::unexpected(a2dp.error());
+    }
+    status.a2dpState = *a2dp;
+    return status;
+}
+
+std::expected<void, bt1035::Bt1035Error> BluetoothService::startPairing()
+{
+    if (auto result = driver_.enterPairingMode(); !result) {
+        return result;
+    }
+    pairingActive_ = true;
+    return {};
+}
+
+std::expected<void, bt1035::Bt1035Error> BluetoothService::stopPairing()
+{
+    if (auto result = driver_.leavePairingMode(); !result) {
+        return result;
+    }
+    pairingActive_ = false;
+    return {};
+}
+
+std::expected<void, bt1035::Bt1035Error> BluetoothService::disconnect()
+{
+    return driver_.disconnectA2dp();
+}
+
+} // namespace bluetooth